: This is a Phase I STTR application from Worcester Polytechnic Institute (WPI) and Centracept, Inc., aimed at improving recovery of therapeutic proteins from cell lysates. The separation method used is continuous flow two- phase electrophoresis; the two phases are formed from a mixture of polyethylene glycol (PEG) and dextran, and the pH is adjusted to render the target protein positively charged, allowing it to be harvested from 5 liters of lysate within 2 hours. Results of the new process will be compared with those of the traditional separation technique employing a combination of centrifugation and filtration. E. coli lysate will be used as a model, and hemoglobin added as a target protein, facilitating monitoring the concentration of the target in different fractions by observation of their color.